You've probably noticed by now that Spain has a confusing number of lotteries, most with similar sounding names.
Lets try to clarify the situationThe Spanish National Lottery (Loteria Nacional) is run by a company called 'Loterias del Estado'. Their portfolio includes the lottery games mentioned here.
The term El Gordo is usually associated with the massive draw held at Christmas, but is also connected with a lotto game which is held once per week on Sundays. What El Gordo actually means is - 'the first prize' or more accurately - 'the big one'.
The La Primitiva lotto (The Primitive One) is Spain's most popular lottery, draws are held twice per week on Thursday and Saturday. The game was called this due to it's age.
The El Gordo de la Primitiva is held once per week on Sundays.
The El Gordo (The Fat One) is held once per year at Christmas.
Bonoloto, held every Monday, Tuesday, Wednesday and Friday.